ZERO STIFFNESS IN DIRECTION 4 AT JOINT    497 EQN.NO.     562
          LOADS APPLIED OR DISTRIBUTED HERE FROM ELEMENTS WILL BE IGNORED.
          THIS MAY BE DUE TO ALL MEMBERS AT THIS JOINT BEING RELEASED OR
          EFFECTIVELY RELEASED IN THIS DIRECTION.
    ZERO STIFFNESS IN DIRECTION 5 AT JOINT    497 EQN.NO.     563
    ZERO STIFFNESS IN DIRECTION 5 AT JOINT    505 EQN.NO.     581
    ZERO STIFFNESS IN DIRECTION 4 AT JOINT    773 EQN.NO.     640
    ZERO STIFFNESS IN DIRECTION 5 AT JOINT    773 EQN.NO.     641
    ZERO STIFFNESS IN DIRECTION 5 AT JOINT    779 EQN.NO.     659
    ZERO STIFFNESS IN DIRECTION 5 AT JOINT    647 EQN.NO.     815
    ZERO STIFFNESS IN DIRECTION 4 AT JOINT    643 EQN.NO.     826
    ZERO STIFFNESS IN DIRECTION 5 AT JOINT    643 EQN.NO.     827
    ZERO STIFFNESS IN DIRECTION 5 AT JOINT    416 EQN.NO.    1055
    ZERO STIFFNESS IN DIRECTION 4 AT JOINT    867 EQN.NO.    1096
    ZERO STIFFNESS IN DIRECTION 5 AT JOINT    867 EQN.NO.    1097

   **WARNING - THERE WERE MORE THAN 12 DOF WITH ZERO STIFFNESS.
               THE FIRST 12 ARE LISTED ABOVE.
               TOTAL # TRANSLATIONAL=     10 TOTAL # ROTATIONAL=     46



   702. FINISH
没搞懂这是怎么回事，请教大家！！

常见问题。
一个节点有6个自由度，如果某个没有被约束就会提示这个，一般是连接某节点的所有杆件都释放了弯矩，那么这个节点的转动自由度就缺少约束，会有这样的提示。
两个杆件铰接，只要释放一个杆件的杆端约束就可以实现了。

非常感谢版主，节点处有时候设半铰，这些地方可能没注意杆件已经被全部打断了的。